Dual front brakes

[jones5944]

I see that this topic is discussed a lot but don't find the answers I was looking for. If my rememberer is working correctly ( which has been getting worse) in 1977 Yamaha came out with a Parts/Tech Bulletin regarding adding dual front brakes. In this bulletin were all the parts and diagrams for adding the left side disc.

If anyone has or has access to this bulletin I would greatly appreciate a copy. I know all the parts that are needed but was wanting to get a detail.

Thanks!

 

[fredintoon]

Hi jones,
what detail? It's so simple even I managed to do it.
You have the leftside caliper, the extra disk and retaining bolts?
You did have the good sense to upgrade to stainless brake hoses when you bought the extra one?
Just fling them on, eh?
Once you get the bastards bled you'll find that the over-large stock master cylinder works perfectly now that it's operating two calipers instead of just one.

 

[jones5944]

Fred:

Thanks for the reply. I know its not hard but just looking for some Yamaha specs and info. I finally found the set up offered by Yamaha in the 79 parts manual which shows all the suggested parts and individual numbers with and exploded view. Was just looking for the actual tech bulletin that came out in 77.

 

[5twins]

Where did you source a left caliper from? I ask because some left side ones come from bikes that used a thinner 5mm thick disc. If that's what you got then you may need to swap out the little pad retainers .....

 

[650Skull]

This what your after

 

[jones5944]

Thanks 5twins and 650skull for the info. I did find this in the 79 parts catalog but I thought there was an earlier tech bulletin that covered this. I am being questioned about an old advertising add that pops up on the internet and talks about the 77 model having dual disc brakes. I know it didn't come that way but was on option and am trying to get some info to back myself up.

5twins: I sourced the entire dual front brake system from a local who's son had started a bobber build (read sawzall,lost interest and left on dads garage floor.) for $50. Measured everything before I bought the system and the rotors were the same thickness.

Thanks guys for the help!

 

[jones5944]

650skull: Just noticed that the info you sent was the 77 Canadian parts catalog. I wonder was the dual brakes offered in Canada and Europe only in77?

 

[650Skull]

Not sure about the Canadian models, maybe it was an option off the floor. I have an 83 Canadian Heritage Special and that was a single disk front brake

Some, if not all Euro models from, and including 75, had twin disk front brakes.

The Euro Standards, from the 77D till 82/3, had twin disk front but the disk was the smaller disk, as per the rear on the Specials. The mounting lugs for the caliper were mounted lower on the fork lower, to accommodate the smaller rotor. The Euro US Custom only had the single disk front brake, disk was the larger one as per the US Specials

Oceania, started the twin disc model for the 76C and all 77D and later models including the Specials had the larger disc, as per the US front one, on a twin disk front brake set up from the factory.

Japanese models appear to have the single disk set up but have seen pics of twin disk models

 

[EvenmoreXS]

Where did you source a left caliper from? I ask because some left side ones come from bikes that used a thinner 5mm thick disc. If that's what you got then you may need to swap out the little pad retainers .....

WTF !!! Adventures in PO begin again !!!

I was looking into swapping to the XS1100 slotted rotors a bit back but some other things took priority and I put my rotors on the back burner since things functioned well.

Now im getting ready to change my front pads and I found an anomaly. Or maybe its just par for the course for me. I never noticed actually measured the rotor thickness until yester day and guess what I found.... I'll wait....

Guess yet... Well I'll tell you any way. They are different thickness's. Like, significantly. Not just wear. See pics.

I am now sourcing to replace both rotors before I put the new pads on.. guess what got posted today... Seriously... Guess.....

These..
http://www.xs650.com/forum/showthread.php?t=45790&highlight=rotors


Before I drop the hammer on these rotors, please help me make sure Im doing it right. Diameter is 298mm. They are not labeled Left or Right but I don't think these are supposed to be like the slotted XS1100 rotors were. They should both work on either side.. Correct?

Per 5twins attached comment I may need to update some shims but I wont be sure until I get in there. If so it looks like I would need the Type 1 .. Is that correct...?

Nothing surprises me after the things I've found from the PO. Im still finding this stuff on the bike. My fault for not looking sooner but she still stops on a dime and all feels well, so I didn't actually measure.


For reference in the pics... The RIGHT rotor is the thin one... not the left.


As always, thanks for the help everyone.




anyone start a " Things the PO did " thread yet... ? I bet it would be scary and hilarious.

 

[arcticXS]

I wonder what a pair of 298 mm diameter and 7 mm thick will weigh.....must be at least 5 lbs EACH....
I swapped my pair of 268mm discs with a single 320 mm ISR disc and a Brembo 4 piston caliper. With an aluminum front fender I lost 5 kgs or 11 lbs of unsprung weight......

Those old discs are really heavy.........

 

[650Skull]

just weighed it and one 298mm rotor and caliper = 9lb 10oz.

The rotor alone is 6lb 10oz

smaller 268mm rotor 3lb 12oz

 

[EvenmoreXS]

That is interesting. Heavy fuckers.

Weight or not I need to replace my rotors. Will the ones I linked in my previous comment work for me. 81 with 35 mm forks. Already set up for dual disc's.

Thanks for the help.

 

[650Skull]

Short answer.....................Yes

 

[EvenmoreXS]

That's what I needed. I figured they were right but damn I hate being wrong.

Thanks skull

 

[Brassneck]

Personally, I'd swap them for the high-performance rotors Mike's Sells...way lighter! I know that's a lot of coin, but 7lbs total weight vs. 18+lbs? That's a big difference.

 

[EvenmoreXS]

No way I can disagree with that logic Brassneck but if im being honest money is a variable at the moment. I don't have the extra 200.00 clams for the HP rotors. The rotors Im interested in are in good shape and will last me a long time. When I build my next bike I will be in it for less money and I will do all the high performance stuff. I just want to keep my daily rider safe and going for now.

 

[5twins]

Note that the shims I have pictured above are the updated "anti-squeal" type. They have little squares of rubber sheet glued in them. You may or may not find this type in your calipers depending how old they are. Only one is required per caliper and it should be in the front position, ahead of the pads. Check both of the shims. Your P.O. may have assembled them wrong, putting the rubber padded shim behind the pad assembly.

If you find that you need new wider shims to fit the 7mm disc, and you haven't sourced new pads yet, you might consider the pad "kit" from Yamaha. In it, you get more than just pads, you get the shims, that top clip, and the special retainer screw for the inner pad with the turned down end .....

And besides that, original Yamaha pads are very good in my opinion. I have supposedly better aftermarket pads in mine now but I don't think they work as well as the originals did. I'm seriously considering putting the old ones back in, lol.

 

[EvenmoreXS]

Excellent 5twins, thanks. I've been sitting on a set of Vesrah pads for a few months waiting until I was ready to install them. I didn't know about the Yamaha pad kit..... Dang.....Looking at that Yamaha set I am tempted to hold on to the vesrah pads and go that route.

Thanks for the great advice.


I've found some on ebay, tell me which ones you think are correct. I believe its the last two.


The shims in the photo look a little different than the ones in your pic. They look like the Type V.

http://www.ebay.com/itm/NOS-1976-19...ash=item4647828cca:g:0PgAAOSwT~9WlxD1&vxp=mtr


There is also this one:

http://www.ebay.com/itm/Yamaha-4K0-...ash=item4d19ccf1d7:g:F8gAAOxyYSdTFkWf&vxp=mtr


And this one:
http://www.ebay.com/itm/251494324330?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

 

[arcticXS]

Just came across these discs, not cheap at all, but lightweight and full floating.

http://www.jl-exhausts.com/jl-brake-disc-352-c.asp

(Should fit XS, as well as RD and TZ)

 

[EvenmoreXS]

Note that the shims I have pictured above are the updated "anti-squeal" type. They have little squares of rubber sheet glued in them. You may or may not find this type in your calipers depending how old they are. Only one is required per caliper and it should be in the front position, ahead of the pads. Check both of the shims. Your P.O. may have assembled them wrong, putting the rubber padded shim behind the pad assembly.

If you find that you need new wider shims to fit the 7mm disc, and you haven't sourced new pads yet, you might consider the pad "kit" from Yamaha. In it, you get more than just pads, you get the shims, that top clip, and the special retainer screw for the inner pad with the turned down end .....

And besides that, original Yamaha pads are very good in my opinion. I have supposedly better aftermarket pads in mine now but I don't think they work as well as the originals did. I'm seriously considering putting the old ones back in, lol.

I've found some on ebay, tell me which ones you think are correct. I believe its the last two.


The shims in the photo look a little different than the ones in your pic. They look like the Type V.

http://www.ebay.com/itm/NOS-1976-198...9WlxD1&vxp=mtr


There is also this one:

http://www.ebay.com/itm/Yamaha-4K0-W...dTFkWf&vxp=mtr


And this one:
http://www.ebay.com/itm/251494324330...:MEBIDX:IT